The present invention pertains to fuzing and more particularly to a pulse Doppler proximity sensor for permitting selectable height of burst fuzing.
Fuzing controls the detonation of munitions at particular times and at particular distances from the earth or other objects. In order for fuzing to detonate munitions at the appropriate time, a proximity sensor of the fuze must determine the range of the fuze with respect to other objects such as the earth. Such fuzing may use radar ranging techniques to determine distance between the munitions and an object.
In low altitude height of burst fuzing situations, there is difficulty in detonation of the munition by the fuzing due to difficulties in detecting the proper range. Height of burst selectability may include detonating at two or more ranges less than 25 feet from an object or target. Presently such radar ranging is accomplished by frequency modulated continuous wave (FM-CW) and by pulsed Doppler technologies. When munitions are deployed in close proximity or clusters, the FM-CW approaches are susceptible to interference between the transmitting and receiving portions of each munition and among the many rounds of munitions deployed. For pulsed Doppler continuous wave applications, the ranging is too short to detect low altitude height for bursts for detonating at less than 25 feet.
Accordingly, it is highly desirable to obtain a proximity sensor for munition fuzing which is very accurate at short range proximity sensing in the presence of a large number of mutually interfering sensors.